Apparatus for rehabilitative exercise of feet

ABSTRACT

Apparatus for rehabilitative exercise of feet is comprised of a cabinet having a pair of motor-driven footboards which swing up and down on their common shaft in the alternatingly opposite directions, while a rehabilitant with his feet on these footboards reclines against a backboard secured to the cabinet. The motor adapted to drive the footboards has a speed control device thereby to controllably vary the speed of their swinging movements. Two additional motors are provided inside the cabinet, one for the adjustment of the angle through which the backboards are permitted to swing and the other for the adjustment of the angle between the centerline of the angle of swing of the backboards and the plane of the horizon, so that the rehabilitant may have his feet exercised the way most suiting his particular case of disability.

United States Patent Kitada APPARATUS FOR REHABILITATEVE EXERCISE OF FEET 1 Feb. 1, 1972 [57] ABSTRACT Apparatus for rehabilitative exercise of feet is comprised of a cabinet having a pair of motor-driven footboards which swing up and down on their common shaft in the alternatingly opposite directions, while a rehabilitant with his feet on these footboards reclincs against a backboard secured to the cabinet. The motor adapted to drive the footboards has a speed control device thereby to controllably vary the speed of their swinging movements. Two additional motors are provided inside the cabinet, one for the adjustment of the angle through which the backboards are permitted to swing and the other for the adjustment of the angle between the centerline of the angle of swing of the backboards and the plane of the horizon, so that the rehabilitant may have his feet exercised the way most suiting his particular case of disability.

9 Claims, 9 Drawing Figures PATENTEU FEB 1 I972 SHEET 3 OF 6 APPARATUS FOR REHABILITATIVE EXERCISE OF FEET BACKGROUND OF THE INVENTION This invention relates to apparatus for rehabilitative exercise of feet, and more particularly to a fully automated apparatus capable of giving a simulated ambulatory exercise to the incoordinated, paralyzed or otherwise affected feet of rehabilitants.

It iswidely held now by physicians and allied scientists that the so-called biorhythm governs the various biological processes of man, and some even assert that reciprocative motion constitutes a basic pattern of all his acts or actions. Walking is a typical example, with the upper'and lower extremities reciprocated in the alternatingly opposite directions in complete coordination. Thus, for the treatment of a rehabilitant with paralyzed or incoordinated limbs as a result of apoplexy or cerebral palsy, for example, it is therapeutically important that his lower extremities be alternately moved back and forth in order to compensate for the forced lack of such reciprocative motion. Similar training of the lower extremities is no less essential for a patient who has been bedridden for an extended period of time, not simply as ambulatory exercise but to facilitate the recovery of his cardiovascular system, which comes later than the recovery of other systems, through the contractive movements of the entire muscles of his legs. The training will thus benefit the patient in manifold ways.

Various types of apparatus have been proposed for the mechanical correction of the affected legs of the rehabilitant. In some such apparatus one or a pair of movable footboards are provided on which are to be placed the feet of the rehabilitant. In order to obtain the best results with this type of ap paratus, however, it is of utmost importance that the movements of these footboards be adjustable according to the degree .of his disability. Too small movements of the footboards will produce no satisfactory results, whole overly great movements may pain and unnecessarily tense the rehabilitant. Hence, the desired corrective effect can be anticipated only when the footboards are moved regularly to a proper degree and at proper speed.

SUMMARY OF THE INVENTION It isa primary object of the present invention to provide apparatus for rehabilitative exercise of feet which is capable of imparting reciprocative motion to the incoordinated, paralyzed or otherwise affected feet of the rehabilitant for the correction of his physical disabilities and his restoration to a condition of health and normal activity.

Another object of the invention is to provide apparatus for rehabilitative exercise of feet, comprising a pair of swingable footboards on which are to be placed the feet of the rehabilitant and which swing up and down in the altematingly opposite directions in order to give him a simulated ambulatory exercise.

Still another object of the invention is to provide apparatus for rehabilitative exercise of feet, so made that the speed of the swing of the footboards is adjustable according to the degree of the disability of each rehabilitant.

Yet another object of the invention is to provide apparatus for rehabilitative exercise of feet, so made that the angle through which the footboards are permitted to swing is adjustable according to the degree of the disability of each rehabilitant in order to prevent him from suffering unnecessary pain or tension.

A further object of the invention is to provide apparatus for rehabilitative exercise of feet, so made that the angle between the centerline of the angle of swing of the footboards and the plane of the horizon is adjustable, especially in consideration of the angle of dorsiflexion or plantar flexion, if any, of each rehabilitant.

Theseand the various ancillary objectsof the invention, as well as the characteristic features thereof, will become more apparent and understandable as the following description proceeds, with reference made to the accompanying drawings showing a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a front elevational view of the apparatus for rehabilitative exercise of feet in accordance with the concepts of the present invention;

FIG. 2 is a right-hand side elevational view of the apparatus of FIG. 1;

FIG. 3 is a cutaway partial left-hand side view showing the inner details of the apparatus of FIG. 1;

FIG. 4 is a cutaway partial rear view also showing the inner details of the apparatus of FIG. 1;

FIG. 5 is a perspective view showing the inner details of the apparatus of FIG. I, with parts thereof being broken away to show other parts in detail;

FIG. 6 is a vertical sectional view taken along the plane of line ll in FIG. 4;

FIG. 7 is a vertical sectional view taken along the plane of line II-II in FIG. 3;

FIG. 8 is a vertical sectional view taken along the plane of line IllIII in FIG. 7; and

FIG. 9 is a cross-sectional view taken along the plane of line lV-IV in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, the reference numeral 1 (FIG. 2) generally designates a cabinet enclosing the driving and other means of the present apparatus for rehabilitative exercise of feet. Framed by means of a plurality of substantially L-shaped steel members, this cabinet 1 includes a front wall 2, sidewalls 3 and 4, a rear wall 5 and a top wall (not shown). While the sidewalls 3 and 4 and the rear wall 5 stand perpendicular to the plane of the horizon, the front wall 2 alone is inclined backwardly, and has at its lower end a frontwardly projecting portion 7 which defines an opening 7. A backboard 8 which may be made of wood or other material is screwed or otherwise attached to the front wall 2, and further provided on this backboard 8 is a cushion 9 which may consist of a cover 9 (made for example of leather, either natural or artificially synthesized) with a wadding 10 of sponge, foamed polyurethane or cotton. Handrails l2 and 13 are secured to the side edges of the backboard 8.

A base 14 of the cabinet 1 is made of substantially U-shaped steel members as seen in FIGS. 3 and 4, and has its front portion 15 extended farther than the lower end of the front wall 2. A pair of brackets 17 and 18, supporting a shaft 16 as in FIG. 1, are welded to the exposed front portion 15 of the base 14, and a pair of spaced-apart footboards l9 and 20 are swingably mounted on this shaft 16.

As seen in FIG. 3, two reinforcing L-shaped steel members provided inside the base 14 of the cabinet 1 supports a bed 23 having an upward projection 24 through which rotatably extends a rod 27 having a worm 28 at one end thereof. Upon the bed 23 there is mounted a carriage 29 so as to be slidable in the axial direction of the rod 27, and this carriage 29 includes a downward projection 30, through which extends the rod 27, and another downward projection 31 having a threaded hole (not shown) for the worm 28 of the rod 27. At the backward end of this rod 27 there is secured a gear 32 which is connected by means of an endless chain 38 to a gear 35 attached to an output shaft 34 of a motor 33, while this motor 33 is screwed (37) to a base 36 disposed horizontally at an upper portion in the interior of the cabinet 1. When the motor 33 is set in motion, therefore, the rod 27 with its worm 28 rotates to move the carriage 29 above the bed 23. As is still to be described in detail, a control circuit of the motor 33 is so arranged that the motor rotation can be selectively reversed thereby to move the carriage 29 in the opposite direction.

As seen in FIG. 4, the carriage 29 includes a portion 39 projecting vertically upwardly, and, in parallel with this projecting portion 39, two vertical support plates 40 and 41 extend whose lower ends are secured to both sides of the carriage 29. A motor 44 adapted to alternatingly swing the footboards 19 and 20 is mounted on a bracket 43 supported by the aforesaid projecting portion 39 and an upper bend 42 of the vertical support plate 40. An output shaft 45 of the motor 44 extends through a bracket 46 secured upon the carriage 29 and is supported by means of a suitable bearing 47 on the bracket 46.

As illustrated in detail in FIGS. 7 and 8, a journal box 48 containing worms 49 and 50 intermeshed at right angles with each other is also mounted upon the carriage 29. These worms 49 and 50 are respectively supported by means of bearing 51 built in the journal box 48, and one of the ends of each or the worms 49 and 50 extends out of the journal box 48. The worm 49 is connected to the output shaft 45 of the motor 44 via a V- belt 54 wrapped round a pulley 53 on the outer extension of the worm 49 and a pulley 52 on the output shaft 45 of the motor 44. The outer extension of the worm 50, on the other hand, is connected to the center of a disk crank 55 having a crankpin 56 provided eccentrically thereto. This crankpin 56 is connected to one of the ends of a crank arm 57, the other end of which is connected by means of a pivot pin 58 to a lower end of a lever 60 supported swingably by a pin 59 secured to the vertical support plate 41.

The swingable lever 60, as illustrated in FIG. 9, is hollow, has a substantially rectangular cross section, and has its lower end closed. In the hollowed interior of this swingable lever 60 there is rotatably installed a worm 61 on which is screwed a nut 62 so as to be movable throughout its length. This nut 62 has a pin 63 extending outwardly of the swingable lever 60 through an elongated cutout slot 64 thereof. One of the ends of the worm 61 is connected, through a reduction gearing 67, to a motor 66 mounted upon a support member 65 secured at the upper end of the swingable lever 60. The rotation of this motor 66 is selectively reversed by means of a control circuit, as is still to be described. Thus, while the motor 66 is in motion, the worm 61 rotates to move the nut 62 longitudinally of the swingable lever 60, in directions determined by the rotational direction of the motor 66.

With reference to FIG. 5, an arm 68 having an elongated cutout slot 69, in which is fitted the pin 63 on the nut 62, is secured to one of the ends of a shaft 70 rotatably supported by the vertical support plates 40 and 41. Accordingly, the arm 68 oscillates on the shaft 70 in accordance with the swing of the lever 60, thus turning the shaft 70 in alternating directions. A shaft 71, extending in parallel with the aforesaid shaft 70, also is rotatably supported by the vertical support plates 40 and 41, and two intermeshed gears 72 and 73 are mounted on these shafts 70 and 71, respectively, so that the shaft 71 turns in the opposite direction in tune with the turn of the shaft 70. Links 74 and 75 are secured at the opposite ends of the shafts 70 and 71, respectively. The free end of the link 74 is pivoted to one of the ends of a rod 76 by means of a pin 78, while the other end of the rod 76 extends through the opening 7 of the cabinet 1 to be pivoted to a flange 21 of the footboard 19 by means of a pin 80. The free end of the link 75, on the other hand, is pivoted to one of the ends of a rod 77 by means of a pin 79, and the other end of this rod 77 similarly extends through the opening 7 of the cabinet 1 to be pivoted to a flange 22 of the other footboard 20 by means of a pin 81.

The example of the present apparatus for rehabilitative exercise of feet, described in the foregoing with reference to the accompanying drawings, is connected to an AC power supply (not shown) when a main power switch 82 (FIG. 2) on the sidewall 3 of the cabinet 1 is turned on. This condition is indicated by means of a pilot lamp 83 on the same sidewall 3. Then, the motor 44 is energized by means of a start switch 84. Since the motor 44 operates on DC power, a rectifying circuit (not shown) is provided which converts the AC power supplied into the desired DC power before its application to the motor 44. Between this motor 44 and the rectifying circuit just mentioned there is provided a speed-changing means, including an adjusting knob 86 on the sidewall 3, capable of changing the rotational speed of the motor 44 according to the voltage applied thereto. The speed-changing means may be so configured that the motor 44 will increase by clockwise turn (in FIG. 2) of the knob 86 and vice versa. I

With the motor 44 thus set in motion, the disk crank 55 (FIG. 5) starts rotation through the pulley 52, the V-belt 54, the pulley 53 and the worms 49 and 50. For each revolution of this disk crank 55 the swingable lever 60 makes one complete reciprocation on its pin 59, and the arm 68 oscillates on the shaft 70. The turns of this shaft 70 in alternating directions cause the footboard 19 to swing up and down on the shaft 16 through the link 74 and the rod 76. The alternating turns of the shaft 70 are also conveyed, with their directions reversed, to the other shaft 71 through the gears 72 and 73 and thence to the other footboard 20 through the link 75 and the rod 77. Hence, this footboard 20 starts swinging up and down in reversed directional relationship with the swing of the aforesaid footboard 19.

A rehabilitant with paralyzed or incoordinated feet as a result of apoplexy or cerebral palsy, for example, may be guided onto the footboards 19 and 20, with his back against the backboard 8 and his hands upon the handrails l2 and 13, before the motor 44 is switched on. The footboards l9 and 20 then start swinging in alternatingly upward and downward directions thereby to give the rehabilitant a simulated ambulatory exercise. Desirably, the speed of the swinging movements of these footboards 19 and 20 should be determined according to a degree of the paralyzation or incoordination of his feet. This purpose is easily accomplished by preadjustment of the rotational speed of the motor 44 by means of the knob 86 of the aforesaid speed changing means, and the speed of the swinging movements of the footboards 19 and 20 so preadjusted is indicated by means of a speed indicator 87 (FIG. 2) on the sidewall 3. In this instance, however, consideration should also be given to an angle through which the footboards l9 and 20 are permitted to swing, because too great an angle of swing may pain or unnecessarily tense the rehabilitant, while too small an angle of swing is likely to render the ambulatory exercise ineffective. The proper adjustment of the angle of swing of the footboards 19 and 20 is therefore of no less importance for the effective remedy of locomotor ataxia. How this angle of swing is adjusted by the present apparatus will now be described with reference to FIGS. 5 and 6.

The motor 66 is so electrically circuited that its connection to the power supply is completed or broken by means of a neutral-biased toggle switch 88 (FIG. 2) on the sidewall 3. Further, when an actuator 89 of this neutral-biased switch 88 is manually moved toward the indicia L, the motor 66 starts rotating the worm 61 in such a direction that the nut 62 thereon slides upwardly. The resultantly reduced angle of swing of the pin 63 secured to the nut 62 causes the arm 68 to swing through a correspondingly reduced angle, thereby decreasing the angle of swing of the footboards 19 and 20. When the actuator 89 of the neutral-biased switch 88 is moved toward the indicia S, on the other hand, the motor rotation is reversed so that the nut slides downwardly of the worm 61. The result is the increased angle of swing of the footboards 19 and 20. These angles of swing of the footboards are shown on an indicator 90 (FIG. 2) through a means not detailed in this specification because this is not considered indispensable for the complete understanding of the present invention.

For still more effective remedy of all possible cases of locomotor ataxia, the present apparatus makes possible the adjustment of not only the speed and angle of the swing of the footboards 19 and 20 but the angle between the centerline of the angle of swing of the same and the plane of the horizon, as described in the following with reference to FIGS. 3 and 5.

The motor 33 is so electrically circuited that its connection to the power supply is completed or broken by means of a neutral-biased toggle switch 91 (FIG. 2) on the sidewall 3. When an actuator 92 of this neutral-biased switch 91 is manually moved toward the indicia U, the motor 33 starts rotating the worm 28 in such a direction that the carriage 29 moves in the direction of the arrow A on the bed 23. This movement of the carriage 29 causes the rods 76 and 77 to move in the same direction thereby to swing the footboards l9 and upwardly on their common shaft 16. When the aforesaid actuator 92 is manually moved toward the indicia U, on the other hand, the motor rotation is reversed so that the carriage 29 moves in the direction of the arrow B. The corresponding movements of the rods 76 and 77 in the same direction cause the footboards l9 and 20 to swing downwardly. It isaccordingly possible to appropriately vary the centerline of the angle of swing of the footboards 19 and 20 by simple manual operations of the switch 91. The angle between this centerline and the plane of the horizon is shown on an indicator 93 (FIG. 2) through a means not dealt with in this specification.

A rehabilitant who has had his feet exercised over a desired length of time by means of the present apparatus may descend from the footboards 19 and 20 after having the motor 44 stopped by means of a stop switch 85 (FIG. 2). There may, of course, be provided another stop switch within easy reach of the rehabilitant on the footboards, so that he may himself stop the operation of the apparatus in event he suffers an unbearable pain.

Although a preferred form of the present apparatus for rehabilitative exercise of feet has been shown and described in the foregoing, it will be obvious that the invention is not to be limited thereby but is to be interpreted broadly and in a manner consistent with the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. Apparatus for rehabilitative exercise of feet comprising:

a pair of pivotally supported footboards on which are to be placed the feet of a rehabilitant, said footboards being disposed in side-by-side relationship and being capable of swinging in the alternatingly opposite directions;

a backboard extending upwardly from near the backward ends of said footboards, said backboard being adapted to support the back of the rehabilitant;

means for moving said footboards in the alternatingly opposite directions, said means including a motor and transmission means interposed between the output shaft of said motor and said footboards, said transmission means being capable of dividing the rotational power produced by said motor in such a manner that said footboards swing in the alternatingly opposite directions;

means for adjusting the angle through which each of said footboards is permitted to swing; and means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon.

2. The apparatus as claimed in claim 1, in which said backboard is attached to a cabinet containing said means for moving said footboards, said means for adjusting the angle of swing of said footboards and said means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon.

3. The apparatus as claimed in claim 2, in which said means for moving said footboards are attached to a carriage installed within said cabinet so as to be slidable toward and away from said footboards.

4. The apparatus as claimed in claim 3, in which said means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon is comprised of a worm rotatably installed within said cabinet and extending through a threaded hole of said carriage, a motor for rotating said worm, and motor control means capable of reversing the rotational direction of said motor, whereby said carriage is moved toward and away from said footboards by means of said motor via said worm so that the relative location of said footboard moving means on said carriage with respect to said footboards varies thereby to swing both of said footboards correspondingly.

5. The apparatus as claimed in claim 1, in which said footboard driving means further comprises speed control means adapted to controllably vary the rotational speed of said motor thereby to correspondingly vary the swinging speed of said footboards.

6. The apparatus as claimed in claim 1, in which said transmission means of said footboard moving means comprises a crank to be rotated by said motor of said footboard moving means, a crank arm connected to said crank, a swingable lever which is pin jointed with said crank arm so as to be moved back and forth by the rotation of said crank, an arm connected to said swingable lever so as to be swung with relation to the swing of said lever, a first shaft secured to one of the ends of said arm so as to be turned in alternating directions by the swing of said arm, a second shaft disposed in side-by-side relationship with said first shaft, a gearing for conveying the alternating turns of said first shaft to said second shaft with their directions reversed, a first link having one of its ends secured to said first shaft, a second link having one of its ends secured to said second shaft, a first rod interconnecting the free end of said first link and one of said footboards, and a second rod interconnecting the free end of said second link and the other of said footboards.

7. The apparatus as claimed in claim 6, in which said means for adjusting the angle of swing of said footboards comprises a worm rotatably installed lengthwise in said swingable lever, a motor mounted on said swingable lever for rotating said worm, a nut member fitted on said worm, said nut member being moved longitudinally of said worm by the rotation of the same, a pin secured to said nut member and extending through an elongated slot of said arm, and motor control means capable of reversing the rotational direction of said motor.

8. The apparatus as claimed in claim 2, in which said backboard is provided with a pair of handrails for supporting the hands of the rehabilitant.

9. The apparatus as claimed in claim 8, in which said backboard is inclined backwardly. 

1. Apparatus for rehabilitative exercise of feet comprising: a pair of pivotally supported footboards on which are to be placed the feet of a rehabilitant, said footboards being disposed in side-by-side relationship and being capable of swinging in the alternatingly opposite directions; a backboard extending upwardly from near the backward ends of said footboards, said backboard being adapted to support the back of the rehabilitant; means for moving Said footboards in the alternatingly opposite directions, said means including a motor and transmission means interposed between the output shaft of said motor and said footboards, said transmission means being capable of dividing the rotational power produced by said motor in such a manner that said footboards swing in the alternatingly opposite directions; means for adjusting the angle through which each of said footboards is permitted to swing; and means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon.
 2. The apparatus as claimed in claim 1, in which said backboard is attached to a cabinet containing said means for moving said footboards, said means for adjusting the angle of swing of said footboards and said means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon.
 3. The apparatus as claimed in claim 2, in which said means for moving said footboards are attached to a carriage installed within said cabinet so as to be slidable toward and away from said footboards.
 4. The apparatus as claimed in claim 3, in which said means for adjusting the angle between the centerline of the angle of swing of said footboards and the plane of the horizon is comprised of a worm rotatably installed within said cabinet and extending through a threaded hole of said carriage, a motor for rotating said worm, and motor control means capable of reversing the rotational direction of said motor, whereby said carriage is moved toward and away from said footboards by means of said motor via said worm so that the relative location of said footboard moving means on said carriage with respect to said footboards varies thereby to swing both of said footboards correspondingly.
 5. The apparatus as claimed in claim 1, in which said footboard driving means further comprises speed control means adapted to controllably vary the rotational speed of said motor thereby to correspondingly vary the swinging speed of said footboards.
 6. The apparatus as claimed in claim 1, in which said transmission means of said footboard moving means comprises a crank to be rotated by said motor of said footboard moving means, a crank arm connected to said crank, a swingable lever which is pin jointed with said crank arm so as to be moved back and forth by the rotation of said crank, an arm connected to said swingable lever so as to be swung with relation to the swing of said lever, a first shaft secured to one of the ends of said arm so as to be turned in alternating directions by the swing of said arm, a second shaft disposed in side-by-side relationship with said first shaft, a gearing for conveying the alternating turns of said first shaft to said second shaft with their directions reversed, a first link having one of its ends secured to said first shaft, a second link having one of its ends secured to said second shaft, a first rod interconnecting the free end of said first link and one of said footboards, and a second rod interconnecting the free end of said second link and the other of said footboards.
 7. The apparatus as claimed in claim 6, in which said means for adjusting the angle of swing of said footboards comprises a worm rotatably installed lengthwise in said swingable lever, a motor mounted on said swingable lever for rotating said worm, a nut member fitted on said worm, said nut member being moved longitudinally of said worm by the rotation of the same, a pin secured to said nut member and extending through an elongated slot of said arm, and motor control means capable of reversing the rotational direction of said motor.
 8. The apparatus as claimed in claim 2, in which said backboard is provided with a pair of handrails for supporting the hands of the rehabilitant.
 9. The apparatus as claimed in claim 8, in which said backboard is inclined backwardly. 